SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd741047a6557c2990d7b994f5cfac31bf2c9c252b642910dcd7ca6bd7f2bd65' 
  AND token = 'QlU5ZPqCMxJFV8JFItfjtdvGMi4PNRF3y9RKiLpvXa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}